Time to chime in here -- "testing" new ads on a live production site with absolutely no heads-up (to the community, not the staff, mind you) is simply bad for business. Yes, I know the staff is privy to recent strife, but that's not my point. We'd all like to see this community generate more revenue -- that's part of what the strife was related to -- and ads are just about the only way to do that.
I agree that non-registered visitors should be shown lots and lots of ads -- but relevant, unobtrusive ones can be shown the logged in users as well. I find it really hard to believe that a billion-dollar industry can't deliver appropriate content.
If PHPFreaks is serious about trying this out, let's set up a private area when staff (and other such beta-testers) can provide feedback on just how broken things are when the ads are running, and take it from there. Flipping switches on & off just strikes me as the wrong approach.